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Interactive Index

Every simulator, game, quiz and interactive figure in the course

46 interactive pieces are linked from the fourteen week pages, scattered across a dozen directories of this site. This page gathers all of them in one place, with 12 more that are relevant but that no week page currently links. Several appear in more than one week — the FID demo turns up in Weeks 02, 03 and 11 — so the per-week counts below add up to more than 46. Search filters on title, description and week. Nothing here needs an install or a login; everything runs in the browser.

Week 01: Introduction & History4

  • Neuroimaging Perspectives: Clinical vs. Research

    Interactive Slide Deck · Conceptual Frameworks

    Explore how clinical radiologists and neuroscientists interpret brain scans differently: qualitative PACS workstations and single-patient pathology vs. quantitative group-level statistics and automated volumetric analysis in research.

    Tool & Primerwk01
  • Diagnostic Test & Confusion Matrix Calculator

    Interactive Tool · Sensitivity, Specificity & PPV

    Manipulate sensitivity, specificity, and disease prevalence to visualize true/false positives and confusion matrices, demonstrating how pre-test probability impacts clinical imaging biomarkers.

    Tool & Primerwk01
  • Neuroimaging Dichotomous Key

    Interactive Decision Tree · Modality Selection

    Step through an interactive dichotomous key to differentiate neuroimaging modalities (CT, SPECT, PET, DSA, EEG, MEG, fMRI, structural MRI, fNIRS, and TCD) based on ionizing vs. non-ionizing radiation, tracers, electromagnetic sensors, and physical contrasts.

    Assessmentwk01wk14
  • Diagnostic Incoming Self-Assessment Quiz

    Formative Assessment · Baseline Knowledge Check

    A quick pre-assessment quiz covering core neuroimaging modalities, signal sources, and spatial/temporal tradeoffs to evaluate your baseline knowledge.

    Assessmentwk01

Week 02: Physical Principles of MRI8

  • Free Induction Decay (FID) & Spin Relaxation

    Faraday Induction & Waveform Simulator · Mxy to FID

    Directly connects the 3D time evolution of precessing and dephasing proton moments to the voltage signal induced in an RF receiver coil via Faraday's Law. Features continuous longitudinal memory across pulses.

    Simulatorwk02wk03wk11
  • Gradient Encoding Visualizer

    Interactive Spatial Encoding Simulator · Gx, Gy, Gz

    Observe how linear magnetic field gradients make precession frequencies position-dependent, demonstrating slice selection (Gz), phase encoding (Gy), and frequency encoding readout (Gx).

    Simulatorwk02
  • Pulse Sequence Timing Diagram

    Interactive Timing Diagram · Spin Echo, TR & TE

    A dynamic pulse sequence diagram. Adjust TE to see the 180° refocusing pulse and echo move together; adjust TR to visualize scanner repetition intervals and phase-encode step increments.

    Simulatorwk02wk03
  • k-space Explorer

    Fourier Reconstruction · Low vs. High Spatial Frequencies

    Vary the fraction of k-space kept to see how central k-space governs coarse contrast while peripheral k-space yields sharp edges, demonstrating Gibbs / truncation ringing.

    Simulatorwk02
  • 3D NMR Relaxation & Proton Dynamics

    Interactive Three.js 3D Simulator · Bloch Equations

    Explore Bloch equation proton spin dynamics in 3D. Manipulate static field strength ($B_0$), $T_1$ recovery, and $T_2$ decay in real-time. Trigger 90° and 180° RF excitation pulses to watch nutation, precession, and magnetization vector evolution.

    Simulatorwk02
  • Interactive 2D FFT & K-Space Simulator

    Dual-Canvas Tool · Spatial Domain & K-Space Magnitude

    Draw spatial patterns or test presets (sine gratings, checkerboards, Gaussian blobs, edge filters) to see the instantaneous 2D Fourier transform magnitude spectrum with DC centering and log scaling.

    Simulatorwk02
  • Spinning Vector Sum Simulator

    Interactive Vector Demo · Phase Coherence

    Adjust rotation frequencies and vector amplitudes to see how multiple precessing magnetic moments combine constructively or destructively to produce the net detected MR signal.

    Simulatorwk02
  • MRI Safety Course & Force Simulator

    Interactive Safety Module · Fringe Fields & Forces

    Examine the spatial fringe field of superconducting magnets with an interactive magnetic attraction force slider ($F \propto B^2$), review projectile safety, and complete the MRI Safety Certification Quiz.

    Tool & Primerwk02

Week 03: Structural MRI & Contrast9

  • Free Induction Decay (FID) & Spin Relaxation

    Faraday Induction & Waveform Simulator · Mxy to FID

    Directly connects the 3D time evolution of precessing and dephasing proton moments to the voltage signal induced in an RF receiver coil via Faraday's Law. Features continuous longitudinal memory across pulses.

    Simulatorwk02wk03wk11
  • Pulse Sequence Timing Diagram

    Interactive Timing Diagram · Spin Echo, TR & TE

    A dynamic pulse sequence diagram. Adjust TE to see the 180° refocusing pulse and echo move together; adjust TR to visualize scanner repetition intervals and phase-encode step increments.

    Simulatorwk02wk03
  • EPI Geometric Distortion & Susceptibility Dropout

    Artifact Physics · Susceptibility ΔB0 & TOPUP

    Examine macroscopic magnetic susceptibility gradients at air-tissue interfaces (paranasal sinuses) that cause phase-encoding distortion and intra-voxel dephasing signal blackout.

    Simulatorwk03wk04
  • TR/TE Contrast Explorer

    Interactive Contrast Simulator · T1, T2 & PD Weighting

    Manipulate TR and TE sliders to see real-time spin-echo signal calculations across four tissue types (White Matter, Gray Matter, CSF, and Fat), dynamically identifying T1-weighted, T2-weighted, and PD-weighted regimes.

    Simulatorwk03
  • MRI Artifact Simulator

    Interactive Artifact Physics · Chemical Shift, Aliasing & Motion

    Introduce deliberate k-space and spatial distortions to inspect Chemical Shift (fat-water frequency displacement), Aliasing / Wrap-around (reduced FOV), and Motion Ghosting (phase-encode modulation) with variable severity.

    Simulatorwk03wk05
  • Spin Echo Dephasing & Rephasing I & II

    Isochromat Grid Simulator · Refocusing & Echo Formation

    Watch an 8x8 array of magnetic moments dephase due to microscopic field inhomogeneities ($T_2^*$), then apply a 180° RF pulse to reverse their relative phase evolution and observe spin echo refocusing.

    Simulatorwk03
  • Ernst Angle Calculator

    Sequence Optimization Tool · Fast Gradient Echoes

    Calculate the optimal excitation flip angle $\alpha_E = \arccos(e^{-TR/T_1})$ to maximize steady-state signal amplitude for gradient echo sequences at short repetition times.

    Tool & Primerwk03
  • Ferroquant: Iron & Hemorrhage Susceptibility Contrast

    Clinical Contrast Primer · Tissue Susceptibility

    Understand how paramagnetic and diamagnetic iron states (oxyhemoglobin, deoxyhemoglobin, methemoglobin, hemosiderin) alter local magnetic fields and shorten $T_2^*$, with a case study on subdural hematoma aging.

    Tool & Primerwk03wk04
  • MRI Modality Card Game

    Educational Card Game · Structural & Contrast Fundamentals

    Reinforce knowledge of MRI magnet types, tissue contrasts (T1, T2, FLAIR, DWI), relaxation physics, and clinical neuro applications.

    Gamewk03

Week 04: Functional MRI (fMRI)6

  • EPI Geometric Distortion & Susceptibility Dropout

    Artifact Physics · Susceptibility ΔB0 & TOPUP

    Examine macroscopic magnetic susceptibility gradients at air-tissue interfaces (paranasal sinuses) that cause phase-encoding distortion and intra-voxel dephasing signal blackout.

    Simulatorwk03wk04
  • fMRI GLM & Convolution Studio

    Analysis Engine · HRF Convolution & BOLD Time Series

    Connect neural events to the BOLD time series by convolving stimulus boxcars with the canonical double-gamma HRF, observing how metabolic delays shape voxel signals.

    Simulatorwk04wk05
  • Interactive BOLD Signal (HRF) Simulator

    Interactive Hemodynamic Simulator · Neurovascular Coupling

    Trigger a 1-second sensory stimulus to contrast instantaneous electrical neural spiking with the sluggish BOLD Hemodynamic Response Function (HRF) peaking 5–6 seconds later, accompanied by a dynamic cortical activation display.

    Simulatorwk04wk05wk12
  • Local Field Potentials (LFP) vs. Spikes

    Population Electrophysiology Simulator · BOLD Signal Origin

    Simulate 150 neurons to see how synchronized postsynaptic potentials (LFPs) create macro-signals that drive astrocytic signaling and metabolic blood flow changes far more strongly than sparse action potentials.

    Simulatorwk04wk08
  • Stochastic Leaky Integrate-and-Fire (LIF) Neuron

    Single-Neuron Biophysics · Metabolic Demand

    Examine the cellular electrophysiological threshold, ion pumping energy requirements, and spike generation that necessitate local hemodynamic overcompensation.

    Simulatorwk04
  • Ferroquant: Iron & Hemorrhage Susceptibility Contrast

    Clinical Contrast Primer · Tissue Susceptibility

    Understand how paramagnetic and diamagnetic iron states (oxyhemoglobin, deoxyhemoglobin, methemoglobin, hemosiderin) alter local magnetic fields and shorten $T_2^*$, with a case study on subdural hematoma aging.

    Tool & Primerwk03wk04

Week 05: fMRI Experimental Design5

  • MRI Artifact Simulator

    Interactive Artifact Physics · Chemical Shift, Aliasing & Motion

    Introduce deliberate k-space and spatial distortions to inspect Chemical Shift (fat-water frequency displacement), Aliasing / Wrap-around (reduced FOV), and Motion Ghosting (phase-encode modulation) with variable severity.

    Simulatorwk03wk05
  • fMRI GLM & Convolution Studio

    Analysis Engine · HRF Convolution & BOLD Time Series

    Connect neural events to the BOLD time series by convolving stimulus boxcars with the canonical double-gamma HRF, observing how metabolic delays shape voxel signals.

    Simulatorwk04wk05
  • Interactive BOLD Signal (HRF) Simulator

    Interactive Hemodynamic Simulator · Neurovascular Coupling

    Trigger a 1-second sensory stimulus to contrast instantaneous electrical neural spiking with the sluggish BOLD Hemodynamic Response Function (HRF) peaking 5–6 seconds later, accompanied by a dynamic cortical activation display.

    Simulatorwk04wk05wk12
  • Flash-Lag Psychophysics Experiment

    Behavioral Paradigm Design · Sensory Presentation

    Experience a classic visual perception timing experiment that illustrates how behavioral psychophysics paradigms are parameterized and synchronized with scanner trigger pulses.

    Simulatorwk05
  • 1D Waveform & Fourier Spectrum Synthesizer

    Web Audio Spectrum Engine · Temporal Filtering

    Explore frequency decompositions and harmonic content to understand why scanner drift (<0.01 Hz) and cardiac/respiratory noise are addressed using high-pass filters and physiological regressors.

    Simulatorwk05

Week 06: Diffusion Tensor Imaging (DTI)3

  • DTI Tensor & Tractography Explorer

    Primary Week Simulator · Tensor Fitting, Streamlines & the Crossing-Fiber Problem

    Shape the diffusion tensor by its eigenvalues and watch the six Stejskal-Tanner gradient measurements it would produce, then seed deterministic streamlines into a synthetic corpus-callosum / corticospinal crossing. Tune the FA stopping threshold, turning-angle limit, step size, and Euler vs. Runge-Kutta integration to see tracts terminate at the intersection, and to see them jump bundles and fabricate a connection when the angle limit is relaxed.

    Simulatorwk06
  • Interactive Fractional Anisotropy (FA) Simulator

    Real-Time Tensor Simulation · Brownian Motion

    Adjust the FA slider from 0.0 to 0.95+ to observe how water diffusion transitions from an isotropic sphere (free fluid in CSF) to a highly constrained ellipsoid parallel to densely packed, myelinated axonal fiber bundles.

    Simulatorwk06
  • 129Xe Microstructural Diffusion Primer

    Restricted Diffusion Physics · ADC Mapping

    Explore how restricted Brownian motion is quantified using Apparent Diffusion Coefficient (ADC) mapping to probe microscopic anatomical barriers.

    Tool & Primerwk06

Week 07: Positron Emission Tomography3

  • Interactive PET Scanner Simulation

    Physics Simulator · Annihilation & LOR Reconstruction

    An interactive simulation of radiotracer decay, positron range, positron-electron annihilation, antiparallel 511 keV gamma photons, coincidence timing windows in the detector ring, and real-time Line of Response (LOR) reconstruction.

    Simulatorwk07
  • X-Ray Water Radiolysis Simulator

    High-Energy Radiation Physics · Photon Attenuation

    Explore photoelectric absorption, Compton scattering, and radical generation during high-energy photon interactions in biological tissue.

    Simulatorwk07
  • PET Modality Card Game

    Educational Card Game · Radiotracers & Oncology

    Assemble complete hands connecting cyclotrons, radiotracers ($^{18}\text{F}$-FDG, $^{15}\text{O}$, $^{11}\text{C}$-PiB), annihilation coincidence detection, and neurodegenerative applications.

    Gamewk07

Week 08: Electroencephalography (EEG)4

  • Local Field Potentials (LFP) vs. Spikes

    Population Electrophysiology Simulator · BOLD Signal Origin

    Simulate 150 neurons to see how synchronized postsynaptic potentials (LFPs) create macro-signals that drive astrocytic signaling and metabolic blood flow changes far more strongly than sparse action potentials.

    Simulatorwk04wk08
  • Interactive Multi-Channel EEG & Artifact Simulator

    Live Waveform Generator · Brainwaves & Artifacts

    Switch between canonical brainwave bands (Delta, Theta, Alpha, Beta, Gamma) across Frontal (Fp1), Central (Cz), and Occipital (O1) channels. Test realistic artifact injection buttons for Eye Blinks (EOG) and Jaw Clenching (EMG).

    Simulatorwk08
  • Hodgkin-Huxley Action Potential Simulator

    Membrane Biophysics · Ion Conductance

    Investigate the voltage-gated $Na^+$ and $K^+$ channel dynamics that govern neuronal excitability and establish the membrane potentials measured by electrophysiological tools.

    Simulatorwk08
  • EEG Modality Card Game

    Educational Card Game · 10-20 System & Diagnostics

    Test your mastery of the International 10-20 electrode system, frequency bands, differential amplifiers, and clinical neurology applications.

    Gamewk08

Week 09: Magnetoencephalography (MEG)3

  • Interactive SQUID Magnetometer vs. Gradiometer Simulator

    Signal Processing Simulator · Noise Cancellation

    Experience why gradiometer configurations (two opposing coils) are critical for measuring femtotesla neural signals: observe how uniform ambient magnetic noise is subtracted out while near-field cortical dipole signals are preserved.

    Simulatorwk09wk13
  • Vector Field & Curl Explorer

    Electromagnetic Principles · Biot-Savart Law

    Visualize vector fields and rotational curl ($\nabla \times \vec{B}$), reinforcing the right-hand rule and magnetic field lines generated by primary intracellular dendritic currents.

    Simulatorwk09
  • MEG Modality Card Game

    Educational Card Game · SQUIDs & Source Localization

    Review superconducting quantum interference devices (SQUIDs), helium cryogenics, magnetically shielded rooms, and presurgical language mapping.

    Gamewk09

Week 10: Functional NIRS (fNIRS)2

  • fNIRS Modified Beer–Lambert Unmixer

    Primary Week Simulator · Extinction Spectra, MBLL & 2×2 Chromophore Separation

    Work through the full optical chain: pick two laser wavelengths against the measured HbO2 and HHb extinction spectra, build the Modified Beer-Lambert matrix from the source-detector separation and differential pathlength factors, then push a simulated hyperemic response forward into two attenuation traces and solve the 2x2 system back to concentrations. Choosing both wavelengths on the same side of the isosbestic point makes the matrix ill-conditioned and reproduces the classic HbO2/HHb crosstalk artifact.

    Simulatorwk10
  • Interactive fNIRS 'Banana Path' & Hemodynamic Simulator

    Optical Diffusion & Hemodynamic Simulator

    Watch animated photons diffuse along the characteristic curved 'banana path' between emitter and detector optodes. Trigger cortical stimulation to observe concurrent tracking of oxygenated hemoglobin ($\text{HbO}$) surge and deoxygenated hemoglobin ($\text{HbR}$) decrease.

    Simulatorwk10

Week 11: Magnetic Resonance Spectroscopy3

  • Free Induction Decay (FID) & Spin Relaxation

    Faraday Induction & Waveform Simulator · Mxy to FID

    Directly connects the 3D time evolution of precessing and dephasing proton moments to the voltage signal induced in an RF receiver coil via Faraday's Law. Features continuous longitudinal memory across pulses.

    Simulatorwk02wk03wk11
  • Interactive MRS Analysis Pipeline & Spectrum Simulator

    Comprehensive Processing Workstation Simulator

    A complete in-browser spectroscopy workstation. Adjust coil thermal noise, toggle the broad macromolecule baseline, apply a 10,000:1 water suppression filter, tune exponential apodization/line broadening (SNR vs. resolution), test zero-filling, and apply zero- and first-order phase corrections.

    Simulatorwk11
  • Hyperpolarized & Multinuclear MRS Primer Hub

    Advanced Spectroscopy Resources · Multinuclear Physics

    Explore advanced spectroscopy protocols including dissolved-phase hyperpolarized Xenon-129 (129xe_dissolved.html), Carbon-13 metabolic flux (13c_liver.html), and jMRUI software workflows (jmrui.html).

    Tool & Primerwk11

Week 12: Multi-modal Integration3

  • Interactive BOLD Signal (HRF) Simulator

    Interactive Hemodynamic Simulator · Neurovascular Coupling

    Trigger a 1-second sensory stimulus to contrast instantaneous electrical neural spiking with the sluggish BOLD Hemodynamic Response Function (HRF) peaking 5–6 seconds later, accompanied by a dynamic cortical activation display.

    Simulatorwk04wk05wk12
  • Kalman Filter Sensor Fusion Simulator

    State-Space Modeling · Sensor Integration

    Tune process noise $Q$ versus measurement noise $R$ to understand how state-space filters combine noisy multi-sensor streams into an optimal hidden state estimate.

    Simulatorwk12
  • NBL 425 Modality Game Center

    Unified Modality Hub · Comparative Review

    Play through all four modality games (MRI, PET, EEG, MEG) to synthesize physical principles, hardware components, and clinical strengths across modalities.

Week 13: Emerging Modalities3

  • Interactive SQUID Magnetometer vs. Gradiometer Simulator

    Signal Processing Simulator · Noise Cancellation

    Experience why gradiometer configurations (two opposing coils) are critical for measuring femtotesla neural signals: observe how uniform ambient magnetic noise is subtracted out while near-field cortical dipole signals are preserved.

    Simulatorwk09wk13
  • Self-Organized Criticality & Scale-Free Dynamics

    Complex Systems Simulation · Neural Avalanches

    Simulate sandpile avalanche distributions and power-law scaling ($1/f$ noise) to examine modern theories of scale-free brain network organization.

    Simulatorwk13
  • Hyperpolarized 129Xe Gas Imaging Primer

    Quantum Polarization Physics · 100,000x Signal Gain

    Explore optical pumping with rubidium vapor to hyperpolarize noble gas nuclei, producing NMR signal enhancements of >100,000-fold that overcome thermal Boltzmann limits.

    Tool & Primerwk13

Week 14: Future & Final Projects3

  • Interactive Spike Sorting (MUA to SUA)

    Machine Learning in Electrophysiology · Clustering

    Experiment with unsupervised K-Means clustering in waveform feature space (amplitude vs. width) to isolate single units from multi-unit recordings, illustrating algorithmic classification in neuroscience.

    Simulatorwk14
  • Neuroimaging Dichotomous Key

    Interactive Decision Tree · Modality Selection

    Step through an interactive dichotomous key to differentiate neuroimaging modalities (CT, SPECT, PET, DSA, EEG, MEG, fMRI, structural MRI, fNIRS, and TCD) based on ionizing vs. non-ionizing radiation, tracers, electromagnetic sensors, and physical contrasts.

    Assessmentwk01wk14
  • NBL 425 Modality Game Center

    Unified Modality Hub · Comparative Review

    Play through all four modality games (MRI, PET, EEG, MEG) to synthesize physical principles, hardware components, and clinical strengths across modalities.

Relevant but not yet on a week page12

These live on the site and bear on the course, but no week page links them. Worth either promoting onto the week they belong to or leaving here as optional depth. The week tag on each is my suggestion, not an existing link.